Elastomeric, chlorosulfonated ethylene polymers are commercially attractive, as once cured to crosslinked products, they are characterized by a number of desirable properties, including (a) resistance to chemical solvents (b) resistance to ozone (c) resistance to abrasion (d) resistance to outdoor weathering and (e) by excellent use temperatures, i.e. flexibility over a temperature range of about -20.degree. C. to about 120.degree. C. Consequently, cured chlorosulfonated ethylene polymers and compositions based thereon, characterized by the properties described above, find uses in many diverse applications including production of film material, as extrudates about wires and cables and as base polymers in flame retardant compositions.
The preparation of chlorosulfonated ethylene polymers has been carried out, in the past, by a solution process wherein the polymers have been reacted with a chlorosulfonation agent, while in a solvent medium. The so-called solution process requires that the solvent be removed from the chlorosulfonated polymer at the completion of the reaction, generally by heating the reacted system at temperatures sufficiently high to drive off the solvent. At the temperatures employed for solvent removal, however, the chlorosulfonated polymer tends to agglomerate and become difficult to handle and process.
It has also been proposed to chlorosulfonate ethylene polymers by a process which involves reacting the polymer with a gaseous chlorosulfonating agent. This process has not been found to be particularly successful as the ethylene polymers have been heterogeneously chlorosulfonated. As pointed out in U.S. Pat. No. 3,347,835, cured products obtained from such chlorosulfonated ethylene polymers have been characterized by inferior properties.